MIDDLESEX — Renewable energy advocates are pushing a 21st century upgrade to an ancient technology — wood heating — as as a way to meet Vermont’s renewable energy goals while revitalizing the state’s struggling forest economy.

Susan Clark purchased a pellet boiler a few years ago to replace an aging oil furnace at her central Vermont home. At a press conference Tuesday, Clark said the lower cost of wood pellets compared to the oil she had been using will eventually make up for the almost $20,000 price tag for the purchase and installation of the boiler.

Advanced wood heating systems — pellet boilers and stoves, and wood chip boilers — produce significantly less air pollution while generating heat more efficiently than their traditional wood stove counterparts. Clark said that heating with a wood pellet boiler has “all the advantages of oil in that a truck comes to your house twice a year and you’ve got fuel” with none of the dust associated with wood stoves.

She pointed to a hole on the side of her house where delivered pellets are sucked through a pipe into a storage tank in her basement. They are then automatically fed into the boiler to heat her house.

Although the new wood heating systems may not be any more complex to use than furnaces, they face many of the same problems that many early-stage technologies do, including a higher upfront cost that can discourage purchase. Currently, there are fewer than 600 advanced wood heating systems installed in the state, according to Olivia Campbell Anderson, director of trade group Renewable Energy Vermont.

Campbell Anderson said at the press conference that nearly 80 percent of homes in Vermont are heated by oil or gas. To meet the state’s renewable energy goals, just shy of 40,000 efficient wood heating systems would need to be installed over the next seven years, she said.

When asked whether that was a “pie in the sky goal,” Campbell Anderson said a combination of incentives and a new tax break will encourage more Vermonters to switch to efficient wood heating.

“There is a plan toward this (goal),” she said, referring to the five-year action plan developed by wood energy proponents last year. “It’s accomplishable — the technology is here.”

The state’s Clean Energy Development Fund and Efficiency Vermont each now offer $3,000 rebates to homeowners who purchase automated wood pellet boilers — potentially shaving $6,000 off the up-front cost. Other utilities around the state, such as Washington Electric Co-op, have additional rebates for customers who purchase these units, said Campbell Anderson.

A rural economic development bill passed at the end of May includes a sales tax exemption for efficient wood heat boilers. Sen. Anthony Pollina, D-Washington, said at the press conference that despite some opposition to the tax break, he and other members of the Senate Agriculture Committee pushed for its inclusion because they see promoting wood heat as an “economic development initiative” for rural Vermont.

As New England paper mills have closed down in recent years, the market for low-grade wood has “dried up,” according to Pollina. “By advancing the use of wood heat boilers, we’re creating a market for that low-grade lumber, which then creates better jobs for loggers and people who work in the woods,” he said, adding that wood pellet plants would create additional in-state jobs.

Emma Hanson, wood energy coordinator for the state Department of Forests, Parks and Recreation, said that the collapse of the state’s low-grade timber market could also lead to a phenomenon known in forestry as “high-grading” — when loggers only harvest high-quality trees for lumber.

High-grading is usually “the last thing that happens before a parcel gets sold,” according to Hanson. Without sufficient forestry income, owners of large tracts of land often start to sell a few acres each year to pay taxes, she said. “That’s when we start to see forest fragmentation and losing forests to development.”

Although few homes in Vermont are currently heated with pellet or wood chip boilers, more than 30 percent of students in the state attend schools that are heated with wood, Hanson added.

Vermont has a history of promoting new forms of renewable energy by providing incentives for early adopters. The state’s solar industry saw explosive growth in megawatts installed and jobs created from 2010-2016, largely due to tax credits that reduced installation costs and fixed prices for net metering.

The state’s Clean Energy Development Fund (CEDF), largely supported by annual payments from Vermont Yankee owner Entergy, provides grants for renewable energy projects around the state. Most of the money from the fund had gone toward solar energy, said Andrew Perchlik, who manages the fund for the Department of Public Service. As installation of solar panels “ramped up” around the state, he began looking for new renewable energy technologies that CEDF could influence with the limited money remaining in the fund.

“What we realized is that focusing on a technology makes a difference,” said Perchlik. “We saw that with a lot of money focused on solar, we could move that market and we thought we could do the same with wood.”